1. Field of the Invention
The present invention relates generally to bandsaw machines of the type having a flexible endless bandsaw blade trained around a plurality of wheels or pulleys to perform a cutting operation and, more particularly, pertains to a guiding apparatus for holding and guiding the bandsaw blade in the bandsaw machine.
2. Description of the Prior Art
The conventional bandsaw machine usually comprises a flexible endless bandsaw blade trained around wheels or pulleys, one of which is driven to drive the bandsaw blade during a cutting operation. One of the stretches of the bandsaw blade trained around the wheels is slidably held or guided by a pair of guide means at the cutting zone so that the bandsaw blade will cut into a workpiece without lateral motion and with reduced vibration. Especially in horizontal bandsaw machines in which the saw head assembly carrying the bandsaw blade is lowered to feed the bandsaw blade into the workpiece, the blade has to be twisted by the guide means to keep the cutting edge of the same faced toward the workpiece. More particularly, the bandsaw blade must be slidably twisted at the cutting zone by the guide means to keep the cutting edge faced vertically downwardly toward the workpiece, since the wheels carrying the bandsaw blade are so disposed that their axes do not lie in a vertical plane but are tilted.
Conventionally, each such guide means comprises a pair of guide members between which the bandsaw blade is slidably inserted with its sides contacted thereby at the cutting zone. One of the guide members is fixedly mounted, and the other one is releasably and adjustably mounted so as to be moved toward and away from the fixed guide member. In this arrangement, the movable guide member is released from the fixed guide member when it is desired to detach the bandsaw blade, and also it is moved toward the fixed guide member to slidably hold the bandsaw blade therebetween.
Heretofore, the movable guide member has been so arranged as to be moved toward and away from the fixed guide member by a screw member. With such an arrangement, difficulties have been encountered in releasing and tightening the screw member to release and hold the bandsaw blade between the fixed and movable guide members each time it is desired to change the bandsaw blade. Also, there is the possibility that the screw member will be improperly adjusted (either too tightly or too loosely), in which event the bandsaw blade is liable to be improperly held by the guide members. In addition, experience has shown that the screw member may become stuck due to rusting or contamination by dust. Furthermore, since it cannot be seen from outside whether the screw member has been tigthened to cause the guide members to hold the bandsaw blade, it has often occurred that the bandsaw blade is put into operation without being held by the guide members with the result that the bandsaw blade will be damaged or broken. This may also result in the workpiece being damaged. The screw-member also makes for a bulky arrangement which restricts its adaptability to the available confined spaces of the bandsaw machine.
In order to overcome the disadvantages of the arrangement using the screw member, attempts have been made at employing hydraulically actuated guide means. However, such alternative arrangements have been found to be unduly costly, complicated, subject to maintenance problems, and more bulky than the arrangements using screw members.